I really don't want you to become a pack rat but there are some things that can help you in the long run if you do hang on to them and low power batteries are one of them.
How you wonder?
Yard sale and consignment sale season are coming up and it's always a great idea to have batteries in electronics or toys you plan to sell.
Instead of purchasing batteries or using full power batteries, insert the low power batteries.
If the 'buyer' wants to test the item, they can.
Storage ideas:
Put them in a plastic bag with your yard sale or consignment kits.